Re: 717215: wrong udp checksum with virtio: workaround and patch
On Wed, Sep 18, 2013 at 12:35:15PM +0200, Holger Levsen wrote:
> so this bug is caused by the virtio driver not populating the UDP checksum and
> thus dhcpd complains about this, see
> https://bugs.launchpad.net/ubuntu/+source/isc-dhcp/+bug/930962
> for more background and a patch for dhcpd.
Why does dhcpd check the checksum, which is already done by the kernel?
> I wonder whether one of the two bugs should be reassigned to the kernel, as
> the root cause is in virtio and not dhcpd.
Why do you think this is a bug in the kernel?
If you use wireshark on any modern hardware, you will always get wrong
checksums for locally generated UDP packets, because the checksum
calculation is offloaded to the hardware. virtio does the same, but
between different VM on the same machine.
Bastian
--
Peace was the way.
-- Kirk, "The City on the Edge of Forever", stardate unknown
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